To be hurt that OH has gone out partying without telling me?

[NotAChocolateRaisin]

I have had to work throughout new years (24 hours for the last four days plus tomorrow) in London, 200 miles from home.
OH didn't pick up phone earlier (v. unusual as we always talk around 11 before bed) and had said earlier that he was just staying in for New Years. (we live together)
Have just gone on Facebook and seen that he is actually having a massive piss up with his mate and a group which will undoubtably include his ex in a city about 30 miles from where we live. He will definitely be sleeping away from home.

Now, I really don't have a problem with him going out (and he certainly doesn't need to tell me) but he lied and the ex thing is knowing at me

I think it could be last minute. I would definitely not see arranging dog to go somewhere and driving for an hour as a big deal. It may be that he knew of friends plans but wasn't going and then had an 'ah f it, I'm going' moment. I've definitely done it!